Mesopredator occurrence and relationships with natural and anthropogenic features in an urban area on the Southern High Plains of Texas

Urban expansion continues to transform undisturbed native land into altered landscapes of roadways and buildings, and is expected to only increase in the coming years. The diminished populations of apex predators in North America has created a vacuum that many mesopredator species have expanded to fill. Many of these species are highly adaptable to the ecosystems urbanization creates and are capably of existing in elevated numbers and densities. These landscapes may also often enable invasive species to thrive and damage biodiversity in these cities. This research focused upon characterizing the assemblage of mesopredators within the city limits of Lubbock, Texas, identifying individual species’ presence and absence at given points throughout the city, and identifying any potential environmental covariates that may be driving their occupancy. Environmental factors at both 100 m and 200 m buffers were measured around each camera location including: anthropogenic land cover (%), canopy cover (%), green space cover (%), manicured grass cover (%), surface water cover (%), total length of road (m), and average automobile daily traffic (AADT); distance to nearest four lane road and year of construction date were also included in analyses. Surveys were conducted during three seasonal deployments (Spring/Summer 2016; Fall 2016; Winter 2017) and captured images of target species including domestic cats (Felis catus), domestic dogs (Canis familiaris), gray foxes (Urocyon cinereoargenteus), red foxes (Vulpes vulpes), raccoons (Procyon lotor), Virginia opossums (Didelphis virginiana), and coyotes (Canis latrans). Cats were most frequented captured on cameras, present at 83% of camera locations and occurring in >30,000 images. Gray foxes were second most frequently encountered, present at 66% of camera locations and occurring in >1,000 images. Coyotes were the second least observed species, occurring at only 6% of camera locations and only occurring in <100 images. Red fox was the least common species in this study, present at only 4.5% of camera locations and only occurring 3 individual times during this study. No habitat features were useful covariates in characterizing factors associated with focal species among all seasons combined. However, some there were some associations for some species within seasons. In general, when feral cats were present, there tended to be more anthropogenic cover and more road traffic than in areas where they were not present. Gray foxes showed very little change in habitat between areas of presence and absence outside of winter and fall, when areas of gray fox presence tended to have <50% anthropogenic cover. Areas of dog presence varied very little from areas of absence regardless of season analyzed. Red foxes were only detected at 3 cameras of all 66 deployed throughout the entire study, and all of these within the summer. As such, no features were related with red fox presence. Coyotes were present at 4 camera locations throughout the entire study, but 4 of these were during fall and only once in summer. It appears that a reasonably low sample size of 66 camera locations, combined with extreme (high or low) occurrence of most focal species made most analytical approaches to understanding features associated with their presence unreliable. It is also likely that whatever, if any, habitat features driving species presence in Lubbock were not among those measured during this research. It is possible anthropogenic food sources (intentionally delivered or not) may be presence of these species in Lubbock, Texas. This is a first attempt to begin to disentangle how these mesocarnivores use this urban landscape, and future efforts certainly need to focus upon feral cats, their movements, and resource use within Lubbock – particularly as related to potential disease risks to people, pets, and native wildlife in this region.